Consumption choices - choices made by a buyer of goods and services. Limited to income and the prices of goods. Budget line - boundary between what is affordable and unaffordable. Points on or under this line is affordable. Points outside the this line are not affordable. Consumption possibilities change when income or prices change. Change in income shifts the budget line to the left/right. Change in prices (of two goods) changes the slope of the budget line. Utility - benefit or satisfaction a person gets from the consumption of goods and services. Total utility - total benefit that a person gets from the consumption of all the different goods and services. Marginal utility - change in total utility that results from a one-unit increase in the quantity of a good consumed. Positive marginal utility, the things that people enjoy and want tom have more of.